Comparison of body weight and adipose tissue in male C57Bl/6J mice fed diets with and without trans fatty acids.

The effect of a diet containing trans-fatty acids (tFA) on the fatty acid composition and fat accumulation in adipose tissue was investigated in mice. Male C57Bl/6J mice were fed Control or Trans Diets that were similar, except that 50% of the 18:1, which was all cis in the Control Diet, was replaced by tFA in the Trans Diet. At selected ages, body weight, epididymal fat pad weight, perirenal fat yield, adipose tissue cellularity and fatty acid composition were examined. Over the time period studied (2-24 mon), the proportion of 18:0 and 16:0 tended to decrease while cis-18:1 levels increased. Compared to the Control Diet, the Trans Diet resulted in adipose tissue lipids with higher percentages of 14:0 and 18:2n-6 and lower percentages of cis-18:1 and 20:4n-6. In polar lipids, tFA replaced saturated fatty acids, whereas tFA replaced cis-18:1 in the nonpolar lipids. Body weights at 16 and 24 mon of age and epididymal fat pad weights at 8-24 mon of age were lower in mice fed the Trans Diet as compared to those fed the Control Diet. At the ages studied, the Trans Diet also resulted in lower values for perirenal fat weights, triacylglycerol to polar lipid ratios, and adipose cell size. The data suggest that chronic consumption of tFA affects lipid metabolism and results in decreased fat accumulation in murine adipose tissue.